The long-term goal of this three-year project is to increase our understanding of the neural processes involved in alcoholism. Alcoholism is characterized by increases in the incentive motivational effects of ethanol, and ethanol associated stimuli, that result in compulsive drug seeking. A prominent theory of addiction hypothesizes that compulsive drug seeking is caused by sensitization of the neural pathways that mediate incentive motivation (Robinson and Berridge, 1993). Recent studies with psychostimulants have provided some support for this theory. The goal of this project is to determine if behavioral sensitization to ethanol alters incentive motivational processes. Changes in incentive motivation will be measured using several different behavioral procedures. Specifically, the experiments will determine if sensitization to the locomotor stimulant effects of ethanol influences stimulus-reward learning (measured by appetitive conditioned approach responses to stimuli associated with reward) and operant responding for reward related stimuli (conditioned reinforcement). In addition, the effects of sensitization on acquisition and expression of conditioned place preference will be examined. DBA/2J mice that consistently sensitize to the locomotor stimulant effects of ethanol will be used as subjects. Initial experiments will identify experimental conditions that produce optimal Pavlovian conditioning to stimuli paired with reward. These conditions will be used in subsequent experiments that will assess the effects of sensitization to ethanol on the incentive motivational effects of these stimuli. Control groups will be included in the experimental design to determine if changes in incentive motivation are specifically associated with sensitization. In summary, the studies proposed in this application will provide evidence that will indicate if behavioral sensitization to ethanol alters incentive motivational processes thereby providing valuable information concerning the role of sensitization in alcoholism.